Rudder construction

Propulsion systems, machinery, turbines, boilers, propellers, fuel consumption, etc.
lwd
Senior Member
Posts: 3822
Joined: Sat Jun 17, 2006 2:15 am
Location: Southfield, USA

Rudder construction

Post by lwd »

The thread over on the axis history forum as a rather interesting question on how rudders on WWII warships were constructed. In particular what materials were used.
Here's the link:
http://forum.axishistory.com/viewtopic. ... 4&t=173740
I looked a bit but couldn't find any details.
User avatar
Herr Nilsson
Senior Member
Posts: 1580
Joined: Thu Oct 21, 2004 11:19 am
Location: Germany

Re: Rudder construction

Post by Herr Nilsson »

German balanced rudders were (almost) empty. There was a little cement in the lover part of the rudder to guarantee that condensed water flows to the lower end of the shaft. The rudders were drained either by being pumped out through the shaft or by using an additional drain bolt, which was located under the lower end of the shaft in case of Bismarck. The plating and inner framework of Bismarck's rudder was made by ST 52 steel. (It seems to me that Tirpitz's rudders were made of ST 42). The rudders were filled with so called "hydrolene" for cavity sealing and drained after 24 hours. The filling hole for this purpose was on top of the rear end of Bismarck's rudder.
Regards

Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)
lwd
Senior Member
Posts: 3822
Joined: Sat Jun 17, 2006 2:15 am
Location: Southfield, USA

Re: Rudder construction

Post by lwd »

Thanks for the reply. Something I'd never really though about but intrigueing.
Would you mind either posting it on the thread I mentioned or mind me doing so?
User avatar
Herr Nilsson
Senior Member
Posts: 1580
Joined: Thu Oct 21, 2004 11:19 am
Location: Germany

Re: Rudder construction

Post by Herr Nilsson »

I'm not registered at the axishistory forum. You can post it there, if you want.
Regards

Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)
culverin
Member
Posts: 60
Joined: Sun Dec 30, 2012 1:31 pm
Location: Near the Itchen Navi

Re: Rudder construction

Post by culverin »


The rudder(s) on any ship are the most critical component.

Forget the size of your ship, weapons, amount of armour or experience of the crew.
If you lose your rudder, you are literally up the creek without a...never a truer phrase.

Yes, RN rudders made extensive use of wood and cork.

Also the corrosion issues on the Van Galen as posted on the other forum mentioned.
Neither am i on that, but shall return re the corrosion and the cause.

Shall post more details on all this shortly. Just seen the time. It's tomorrow today already.
A full broadside. The traditional English salute.
Thanks. Sean.
culverin
Member
Posts: 60
Joined: Sun Dec 30, 2012 1:31 pm
Location: Near the Itchen Navi

Re: Rudder construction

Post by culverin »

Almost all warships have balanced rudders, unlike merchant ships.

In the British RN there were 2 separate types.
The larger ships, some cruisers and above, often had their rudder supported mid way by a pintle due to the weight.

The much more common was a balanced rudder whose rotating axis, the part which penetrates the hull, has no pintle.
That axis point then has approx 1/3rd of the rudder ahead and 2/3rds abaft.
Construction is a steel frame inbetween which is solid fir or slab cork filling. This then has a special coating before the 8lb, about 1/4" plates are riveted to the frame thereby visually concealing the internal materials. The leading edge is reinforced.

The wood used, fir and slab cork was very lightweight. Elm was also used for a few other components on the larger rudders. All 3 are extremely durable in sodden conditions.
A full broadside. The traditional English salute.
Thanks. Sean.
Post Reply